Digital and mixed digital-analog circuits and systems may operate based on timing clocks which may be generated from a master timing clock. These timing clocks may be generated using a programmable phase-locked loop (PLL) and associated control circuitry. However, PLLs are limited in their ability to generate signals with precise phase relationships.
Because state-of-the-art circuits and systems may require generation of clock signals that are more precise than clock signals generated using traditional PLLs, phase interpolator circuits may be used to provide improved timing control over circuits and systems that rely on precise timing.
A phase interpolator is a circuit element that adds two or more signals having different phases and provides a single output having a phase somewhere between the phases of the input signals. Accordingly, phase interpolators may be used in applications in which precise timing is desirable; however, phase interpolators may exhibit integral non-linearity, which may limit the accuracy of the timing control provided by a phase interpolator.